.App-header {
  background-color: #282c34;
  min-height: 10vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: calc(10px + 2vmin);
  color: white;
}

.page {
  display: flex;
  height: 90vh;
}

.content {
  flex: 4;
  background-color: #f0f0f0;
  padding: 20px;
  display: flex;
  flex-direction: column;
  text-align: left;
}

.content.highlight {
  background-color: yellow;
}

.sidebar {
  flex: 1;
  background-color: #d0d0d0;
  padding: 20px;
}

.line-number {
  display: inline-block;
  width: 30px;
  text-align: right;
  margin-right: 10px;
  color: #888;
}

.text-symbol {
  position: relative;
  display: inline-block;
}

.hovercard {
  display: none;
  position: absolute;
  top: -40px;
  left: 0;
  background-color: white;
  border: 1px solid #ccc;
  padding: 5px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
  z-index: 10;
}

.text-symbol:hover .hovercard {
  display: block;
}